We investigated photochromic behavior, i.e. X-ray irradiation and post-heat-treatment-induced reversible redox and clusterization reactions of silver, in soda-lime silicate (74SiO(2)center dot 16Na(2)O center dot 8CaO center dot 2Al(2)O(3)) and aluminosilicate ((75 - x) SiO(2)center dot 25Na(2)O center dot xAl(2)O(3) (x = 5-25)) glasses. Generation and annihilation of silver nanoparticles were observed for soda-lime silicate and x = 5 aluminosilicate glasses doped with 0.05 wt.% or less of Ag while no nanoparticles were formed for x = 15-25 aluminosilicate glasses even doped with 0.5 wt.% of Ag. These results were analyzed from the viewpoints of the reaction kinetics and network structures of the glasses. (C) 2011 Elsevier B. V. All rights reserved.